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Every fleet has at least one vehicle everybody argues about – the one that still runs, still passes inspection, and still swallows money every quarter. Replacing too early wastes capital that is doing useful work. Replacing too late costs more in repairs and lost days than a payment would have. The decision is not really about the vehicle’s age; it is about where it sits on its own cost curve.
Age and mileage are a trigger, not a verdict
Most structured fleets set an age and a mileage threshold and review a vehicle when it crosses either one. That is a sensible way to make sure nothing is forgotten, but the threshold itself does not decide anything. Two vans of the same age, doing the same distance, can be in completely different condition depending on load, terrain, driver and how well the servicing was kept up.
Treat the threshold as the moment the vehicle joins the review list, and then make the decision on its actual numbers.
What a published replacement schedule looks like
It helps to see how a large, cost-disciplined fleet sets its thresholds. The State of California publishes its replacement criteria openly, and a vehicle becomes eligible when it reaches either the age or the mileage figure:
- Sedans – 72 months or 65,000 miles
- Cargo vans – 60 months or 65,000 miles
- Pickup trucks – 60 months or 65,000 miles
- Mini vans – 96 months or 80,000 miles
- Sport utility vehicles – 84 months or 85,000 miles
- Trucks, vans and SUVs from 8,501 to 16,000 lb GVWR – 72 months or 70,000 miles
- Trucks, vans and SUVs from 16,001 to 26,000 lb GVWR – 132 months or 115,000 miles
Two things are worth taking from that table. Heavier vehicles are kept far longer, because they are built to work longer and cost more to replace. And the schedule explicitly allows earlier replacement where a mechanical assessment justifies it – the numbers open the conversation rather than closing it.
The cost curve that actually decides
A vehicle’s cost per kilometre follows a predictable shape. Depreciation is steepest early, so the first years are expensive even though nothing breaks. Maintenance is low at first, then climbs. Added together, total cost per kilometre falls to a floor somewhere in the middle of the vehicle’s life, sits there for a while, and then starts to rise as repairs take over from depreciation.
The right time to replace is when the curve has clearly turned upwards and is not coming back – not at the first expensive repair. One gearbox in an otherwise sound vehicle is an event, not a trend. Three unplanned repairs in a year, rising consumption and a tyre bill that keeps growing is a trend.
This is why the replacement decision and the total cost of ownership calculation are the same exercise done at different times. If you kept per-vehicle records from the start, the answer is already in them.
Downtime is the cost people leave out
Repair invoices are easy to count. The day the vehicle spent on a ramp is not, and for a small fleet it is often the larger number: a job not done, a customer rescheduled, sometimes a hire vehicle on top.
Track days off the road per vehicle per year alongside repair spend. A vehicle with modest repair bills but repeated short outages can be costing more than one with a single large invoice, and it is the one most likely to fail at the worst moment.
Signs a vehicle has turned
- Unplanned repairs have become routine rather than exceptional.
- Fuel or energy consumption has drifted upward and stayed there after servicing.
- The vehicle is off the road often enough that work is planned around it.
- The next scheduled job is a major one – timing chain, clutch, turbo, battery pack – on a vehicle already past its threshold.
- Drivers have started avoiding it. This is soft evidence and it is usually right.
When keeping it is the better call
Replacement is not automatically the disciplined choice. A vehicle that is past its age threshold but lightly used, well maintained and doing a job it suits can be the cheapest asset in the fleet. Low-utilisation vehicles in particular often should not be replaced – they should be questioned, because a vehicle that barely moves is a vehicle you may not need at all.
Where replacement is genuinely deferred, defer it deliberately: agree what would change the decision, plan the next major service, and put the money aside rather than discovering it later.
Plan replacements, do not react to them
The worst version of this decision is the one made on the day a vehicle fails, when the choice is whatever a dealer can supply this week. Keep a rolling view of which vehicles cross their thresholds in the next twelve months, and stagger them so the fleet does not need replacing all at once.
That also gives you room to change vehicle type rather than replacing like with like – which is the natural moment to ask whether the next one should be electric, smaller, or not replaced at all.
Related guides
- The Real Cost of a Fleet Vehicle: Total Cost of Ownership
- Fleet Management for Beginners: The First-Year Playbook
- How to Reduce Fleet Fuel Costs
- Fleet Electrification: Planning the Switch to EVs
